The present invention is directed to circuit breakers, and more particularly to interlock mechanisms to trip the circuit breaker when a motor operator is separated therefrom.
Circuit breakers include movable and fixed contacts for opening and closing the distribution circuit and an operating handle for manually operating the contacts. In some installations of industrial rated molded-case circuit breakers, it is convenient or necessary to install a motor operator allowing remote operation the circuit breaker. For example, remote operation may be desired when the circuit breaker is located remote from associated equipment. Motor operators mount directly on the circuit breaker and include a chuck or drive slide that engages the manual operating handle, and moves the operating handle under force of some actuating mechanism within the motor operator housing.
Prior art motor operators include a blocking arrangement to prevent closure or installation of the motor operator when the circuit breaker operating handle is out of alignment with the motor operator. A drawback of this blocking arrangement has been a potential for damage to the motor operator if a person applies excessive force attempting to close the motor operator when the operating handle and operator chuck are out of alignment.
The above discussed and other drawbacks and deficiencies are overcome or alleviated by an operating mechanism comprising an operating handle movable between on and off positions, the operating handle extending substantially up at a point between said on and off positions; a crank for controlling a contact arm of a circuit breaker to cause the contact arm to move between open and closed positions when the crank moves; mechanism springs connected between the operating handle and crank so that the crank moves when the mechanism springs are discharged and when the operating handle is moved between on and off positions; a trip latch restraining the mechanism springs from discharging unless moved; and a trip lever having a lever arm, the trip lever being biased by a tripping spring to cause the trip lever to extend substantially up from the operating mechanism and move the trip latch and discharge said mechanism springs unless the trip lever is prevented from rotating under the influence of said tripping spring.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.